Optimized synchronization preamble structure

Abstract

Orthogonal Frequency Division Multiplexed transmission and reception using a broadcast burst preamble. The preamble comprises at least one first part (A-FIELD) designed for a coarse frame detection and/or an AGC control, and at least one second part (B-FIELD) following the at least one first part in the time domain and being designed for a timing and frequency synchronization. The at least one first part (A-FIELD) and the at least one second part (B-FIELD) each include Inverse Fast Fourier Transformed (IFFT) frequency domain sequences of complex symbols. The frequency domain sequence of the at least one first part (A-FIELD) is set depending on the frequency domain sequence of the at least one second part (B-FIELD) such that a second autocorrelation peak mainly generated by the at least one second part (B-FIELD) of the preamble is optimized. The sequence of complex symbols of the first part differs from the sequence of complex symbols of the second part in at least one symbol.

1. A method of generating and transmitting a preamble signal in an OFDM (Orthogonal Frequency Division Multiplexing) system, comprising the steps of:
 generating said preamble signal comprising at least a first part, a second part following said first part in the time domain, and a third part following said second part in the time domain, wherein said first part is designed for a frame detection and/or an AGC (automatic gain control), said second part is designed for a coarse timing and frequency synchronization, and said third part is designed for fine synchronization, and wherein each of said first and second parts contains a frequency domain sequence comprising 12 complex symbols mapped on every four subcarriers of all available 52 subcarriers of said ODFM system, and said third part contains 52 symbols, each set to 1 or −1, mapped on said all available 52 subcarriers; 
 generating a time domain signal from said preamble signal by performing an inverse fast Fourier transform (IFFT) on said frequency domain sequences; and 
 transmitting said time domain signal from a transmitter-side to a receiver side of said OFDM system; 
 wherein said 12 complex symbols in the frequency domain sequences of said first and second parts are set so that a synchronization performed in the receiver side includes correlating said frequency domain sequence of said first part and said frequency domain sequence of said second part, and a last six symbols of the first part are each identical to each of respective last six symbols of the second part. 
 
     
     
       2. A device for generating and transmitting a preamble signal in an OFDM (Orthogonal Frequency Division Multiplexing) system, comprising:
 a preamble signal generator configured to generate said preamble signal comprising at least a first part, a second part following said first part in the time domain, and a third part following said second part in the time domain, wherein said first part is designed for a frame detection and/or an AGC (automatic gain control), said second part is designed for a coarse timing and frequency synchronization, and said third part is designed for fine synchronization, and wherein each of said first and second parts contains a frequency domain sequence comprising 12 complex symbols mapped on every four subcarriers of all available 52 subcarriers of said ODFM system, and said third part contains 52 symbols, each set to 1 or −1, mapped on said all available 52 subcarriers; 
 a time domain signal generator configured to generate a time domain signal from said preamble signal by performing an inverse fast Fourier transform (IFFT) on said frequency domain sequences; and 
 a transmitter configured to transmit said time domain signal from a transmitter side to a receiver side of said OFDM system; 
 wherein said 12 complex symbols in the frequency domain sequences of said first and second parts are set so that a synchronization performed in the receiver side includes correlating said frequency domain sequence of said first part and said frequency domain sequence of said second part, and a last six symbols of the first part are each identical to each of respective last six symbols of the second part. 
 
     
     
       3. A method of generating and transmitting a preamble signal in an OFDM (Orthogonal Frequency Division Multiplexing) system, comprising the steps of:
 generating said preamble signal comprising at least a first part, a second part following said first part in the time domain, and a third part following said second part in the time domain, wherein said first part is designed for a frame detection and/or an AGC (automatic gain control), said second part is designed for a coarse timing and frequency synchronization, and said third part is designed for fine synchronization, and wherein each of said first and second parts contains a frequency domain sequence comprising 12 complex symbols mapped on every four subcarriers of all available 52 subcarriers of said ODFM system, and said third part contains 52 symbols, each set to 1 or −1, mapped on said all available 52 subcarriers; 
 generating a time domain signal from said preamble signal by performing an inverse fast Fourier transform (IFFT) on said frequency domain sequences; and 
 transmitting said time domain signal from a transmitter side to a receiver side of said OFDM system; 
 wherein said 12 complex symbols in the frequency domain sequence of said first part correlates to said 12 complex symbols in the frequency domain sequence of said second part so that a correlation peak is generated by said timing and frequency synchronization performed in said transmitter side with said second part, and a last six symbols of the first part are each identical to each of respective last six symbols of the second part. 
 
     
     
       4. A device for generating and transmitting a preamble signal in an OFDM (Orthogonal Frequency Division Multiplexing) system, comprising:
 a preamble signal generator configured to generate said preamble signal comprising at least a first part, a second part following said first part in the time domain, and a third part following said second part in the time domain, wherein said first part is designed for a frame detection and/or an AGC (automatic gain control), said second part is designed for a coarse timing and frequency synchronization, and said third part is designed for fine synchronization, and wherein each of said first and second parts contains a frequency domain sequence comprising 12 complex symbols mapped on every four subcarriers of all available 52 subcarriers of said ODFM system, and said third part contains 52 symbols, each set to 1 or −1, mapped on said all available 52 subcarriers; 
 a time domain signal generator configured to generate a time domain signal from said preamble signal by performing an inverse fast Fourier transform (IFFT) on said frequency domain sequences; and 
 a transmitter configured to transmit said time domain signal from a transmitter side to a receiver side of said OFDM system; 
 wherein said 12 complex symbols in the frequency domain sequence of said first part correlates to said 12 complex symbols in the frequency domain sequence of said second part so that a correlation peak is generated by said timing and frequency synchronization performed in said transmitter side with said second part, and a last six symbols of the first part are each identical to each of respective last six symbols of the second part. 
 
     
     
       5. A method of generating and transmitting a preamble signal in an OFDM (Orthogonal Frequency Division Multiplexing) system, comprising the steps of:
 generating said preamble signal comprising at least a first part, a second part following said first part in the time domain, and a third part following said second part in the time domain, wherein said first part is designed for a frame detection and/or an AGC (automatic gain control), said second part is designed for a coarse timing and frequency synchronization, and said third part is designed for fine synchronization, and wherein each of said first and second parts contains a frequency domain sequence comprising 12 complex symbols mapped on every four subcarriers of all available 52 subcarriers of said ODFM system, and said third part contains 52 symbols, each set to 1 or −1, mapped on said all available 52 subcarriers; 
 generating a time domain signal from said preamble signal by performing an inverse fast Fourier transform (IFFT) on said frequency domain sequences; and 
 transmitting said time domain signal from a transmitter side to a receiver side of said OFDM system; 
 wherein said 12 complex symbols in said frequency domain sequences of the first and second parts have correlation properties set for said timing and frequency synchronization process performed in said receiver side, and a last six symbols of the first part are each identical to each of respective last six symbols of the second part. 
 
     
     
       6. A device for generating and transmitting a preamble signal in an OFDM (Orthogonal Frequency Division Multiplexing) system, comprising:
 preamble signal generator configured to generate said preamble signal comprising at least a first part, a second part following said first part in the time domain, and a third part following said second part in the time domain, wherein said first part is designed for a frame detection and/or an AGC (automatic gain control), said second part is designed for a coarse timing and frequency synchronization, and said third part is designed for fine synchronization, and wherein each of said first and second parts contains a frequency domain sequence comprising 12 complex symbols mapped on every four subcarriers of all available 52 subcarriers of said ODFM system, and said third part contains 52 symbols, each set to 1 or −1, mapped on said all available 52 subcarriers; 
 time domain signal generator configured to generate a time domain signal from said preamble signal by performing an inverse fast Fourier transform (IFFT) on said frequency domain sequences; and 
 a transmitter configured to transmit said time domain signal from a transmitter side to a receiver side of said OFDM system; 
 wherein said 12 complex symbols in said frequency domain sequences of the first and second parts have correlation properties set for said timing and frequency synchronization process performed in said receiver side, and a last six symbols of the first part are each identical to each of respective last six symbols of the second part. 
 
     
     
       7. A method of generating and transmitting a preamble signal in an OFDM (Orthogonal Frequency Division Multiplexing) system, comprising the steps of:
 generating said preamble signal comprising at least a first part, a second part following said first part in the time domain, and a third part following said second part in the time domain, wherein said first part is designed for a frame detection and/or an AGC (automatic gain control), said second part is designed for a coarse timing and frequency synchronization, and said third part is designed for fine synchronization, and wherein each of said first and second parts contains a frequency domain sequence comprising 12 complex symbols mapped on every four subcarriers of all available 52 subcarriers of said ODFM system, and said third part contains 52 symbols, each set to 1 or −1, mapped on said all available 52 subcarriers; 
 generating a time domain signal from said preamble signal by performing an inverse fast Fourier transform (IFFT) on said frequency domain sequences; and 
 transmitting said time domain signal from a transmitter side to a receiver side of said OFDM system; 
 wherein said 12 complex symbols in the frequency domain sequence of said first part are correlated with said 12 complex symbols in the frequency domain sequence of said second part for said timing and frequency synchronization process performed in said receiver side, and a last six symbols of the first part are each identical to each of respective last six symbols of the second part. 
 
     
     
       8. A device for generating and transmitting a preamble signal in an OFDM (Orthogonal Frequency Division Multiplexing) system, comprising:
 preamble signal generator configured to generate said preamble signal comprising at least a first part, a second part following said first part in the time domain, and a third part following said second part in the time domain, wherein said first part is designed for a frame detection and/or an AGC (automatic gain control), said second part is designed for a coarse timing and frequency synchronization, and said third part is designed for fine synchronization, and wherein each of said first and second parts contains a frequency domain sequence comprising 12 complex symbols mapped on every four subcarriers of all available 52 subcarriers of said ODFM system, and said third part contains 52 symbols, each set to 1 or −1, mapped on said all available 52 subcarriers; 
 time domain signal generator configured to generate a time domain signal from said preamble signal by performing an inverse fast Fourier transform (IFFT) on said frequency domain sequences; and 
 a transmitter configured to transmit said time domain signal from a transmitter side to a receiver side of said OFDM system; 
 wherein said 12 complex symbols in the frequency domain sequence of said first part are correlated with said 12 complex symbols in the frequency domain sequence of said second part for said timing and frequency synchronization process performed in said receiver side, and a last six symbols of the first part are each identical to each of respective last six symbols of the second part.